Dear Castle
by Castle of Serenity
Summary: "Castle lingered a moment longer, and when he glanced down as he stood, he noticed the edge of a notebook peeking out from underneath Beckett's desk. He grabbed it, then turned towards the direction she had gone. 'Beckett,' he called. 'You forgot your…' It was too late. By the time he had shouted, the elevator doors had closed." Set early season 4. Three-shot.
1. Chapter 1

**AN: For those of you reading my other story, don't worry, I'm still working on the next chapter. I just got this idea for a story in my head and it was begging to be written. I do have to warn you that the majority of this was written at three in the morning. I've made a few touch-ups, but those were made at three in the morning the following day. This is what happens when I have three day weekends.**

 **Disclaimer: I own no part of Castle or its characters, nor will I by the time I finish this story.**

* * *

Castle returned from the break room where he had been talking to Ryan and Espo about their latest case, two coffee mugs in hand. He had been gone for only ten minutes, Beckett grumbling something about paperwork. The case had been solved only the day before, and it had been a late night. As it had been late, they hadn't been able to get a warrant for their suspect's arrest until this morning. Now that the man was in holding, all that was left to do was paperwork.

When he sat down in his chair, he noticed that Beckett seemed to have nodded off. Her head was propped up on the heel of her hand, and her hair was shielding her face, the same position she had been in when he got up to get coffee. From a distance, she probably looked as though she was focused on the form in front of her, and the only reason Castle had known she was asleep was because of her lack of response when he set her mug down on her desk. He wondered if she had fallen asleep before he had even gone to the break room.

Gently, he gave her shoulder a small shake. She let out a small grunt in protest, but her eyes fluttered open. Squinting, she raised her head and look at him.

"Castle?" she asked, her voice thick with sleep.

"You dozed off, I'm not sure how long you've been out," he told her, then smiled. "Don't worry, I won't tell Gates."

She nodded her thanks, yawned, then sat up in her chair a little straighter. "What time is it?"

Castle checked his watch. "About a quarter after four."

Beckett's eyes went wide, and suddenly she was out of her chair and hurriedly putting things away.

"Beckett, what's going on?"

"I have an appointment at four-thirty," she explained as she threw pens into the cup on her desk. "Damn it, I'm going to be late."

Castle was out of his chair in an instant. "I'll clean up, Kate. You worry about your appointment." He knew that it had to be important for her to be rushing like this, so he was ready to give her as much time as possible.

"Thank you," she said as she reached for her purse. Unfortunately, in her haste, she only grabbed one strap and the contents spilled out onto the floor.

Muttering obscenities, she crouched to the floor and started to throw them back into her bag. Castle was only a second behind, and once everything had been replaced, she was half-jogging towards the elevator.

At least, they thought it had been everything.

Castle lingered a moment longer, and when he glanced down as he stood, he noticed the edge of a notebook peeking out from underneath Beckett's desk. He grabbed it, then turned towards the direction she had gone.

"Beckett," he called. "You forgot your…" It was too late. By the time he had shouted, the elevator doors had closed. He looked stupefied towards the elevator, then turned back to his partner's desk, starting on putting all of the forms back into folders, leaving the notebook in the middle for him to decide what to do with later.

"Mr. Castle," Gates' voice came from the door to her office. "Where has Detective Beckett run off to?"

"She had an appointment, sir," he responded. He had expected her to ask what the appointment was, but the captain nodded at the information.

"Yes, she mentioned having to leave this morning. I take it she's running late?"

Castle nodded quickly. "She got caught up with paperwork and lost track of time."

"Well, at least she was working," Gates mused. "You can go home now, Mr. Castle."

"Yes, sir," he replied, trying to keep the dejection out of his voice. Gates took any opportunity to get him out of the precinct. The boys poked their heads out of the break room, having seen the entire scramble.

"You leaving for the day?" Esposito asked as he walked back to his desk.

"I told Beckett I'd clean up her desk, but then I'll be gone. Probably catch up on some writing."

"Are you coming by for lunch tomorrow?" Ryan asked.

Castle nodded. "Sure. Want me to pick up Chinese for you guys?"

The pair let out happy sighs. "Thanks, man," Esposito said.

As the two detectives got themselves situated to do their paperwork, Castle replaced folders back into the drawers he knew them to always be in, then looked back at the notebook, conflicted. He wasn't sure whether to leave it here or not. Thinking that it was likely something personal, he opted to take it home with him, then call her about it later. Odds were that she didn't want people looking at it, and if he were to leave it on her desk, anyone could pick it up, or maybe the boys would get curious about what it was since no one had ever seen it before.

"See you tomorrow, guys," he called before he walked towards the elevator, Beckett's notebook tucked into his jacket. Ryan and Esposito called out their farewells, and he turned to leave.

* * *

Since Alexis was at a study group with her friends, and his mother was out doing whatever she does when she goes out, Castle had the loft to himself. He spent much of his time pacing around the living room, Beckett's notebook sitting in the middle of his coffee table. He should text her, let her know where it is in case she misses it, but he couldn't bring himself to do it. He wanted— no, _needed_ to know what was in that notebook, but he didn't want to invade her privacy. If it was something personal, there was a good chance she wouldn't want to speak to him if she found out.

A glance at the clock told him that he had been fussing about this to himself for nearly half an hour, and finally, he came up with a solution. He'd open the front page, read the first few words to figure out what it was, then never open it again. It would be easy.

He picked it up and held it in his hands for a minute. Taking a deep breath, he flicked open the front cover, saw two words and immediately snapped it shut. Two words. Two words that made his world stop spinning for a moment before his mind started whirring with possibilities for what they meant:

 _Dear Castle..._

They only made him want to read more, to know exactly what she had written on the rest of the page, the rest of the journal. He wanted to know what she could have possibly written, what she was writing to _him._ He wanted to know everything she had to say to him, what could be so important that she felt the need to write it down. He knew he shouldn't, so he didn't.

For about an hour.

For an hour, he sat down and wrote a few decent paragraphs, but his eyes kept wandering to where the notebook now lay on his desk. After an hour, he gave in. He opened up the front cover, and read the first section.


	2. Chapter 2

**AN: This chapter is just what Kate wrote in the notebook, and the next chapter is Castle bringing the notebook to her. Both chapters were written at the same time, which was from about midnight to four in the morning, so I can't guarantee they make total sense. Hopefully, it's not too bad, and please review with any suggestions or comments!**

 **Disclaimer: I still don't own Castle; what a surprise.**

* * *

 _Dear Castle,_

 _I feel ridiculous writing all of this down. I should be telling you this in person, but here I am, hiding in the woods in my dad's cabin. I wish I was with you, either in your loft or maybe you out here with me. I guess that's what I get for not calling. Even if I did call you, I have no idea what I'd say. It's already been a month since I told you I'd call. Maybe you don't even care anymore, maybe you've moved on. At the very least, you're probably angry. You should be angry, deserve to be._

 _I keep thinking back to that day in the cemetery. I was so messed up. It was like everything I knew was being ripped apart. I guess being out here has been good for me, in that sense. I'm not thinking about everything that happened with Montgomery anymore, but I guess that's because my mind is focused elsewhere._

 _It's almost funny how I've gotten better being out here, but at the same time so much worse. Physically, I'm better than I was the last time I saw you, which was at the hospital. God, that was so long ago. I feel like I haven't seen you in years. You've left such a big hole. I think my dad is getting suspicious. He knows I'm hurting, but he doesn't know why. Well, maybe he does and he's not saying anything. I haven't told anyone about what you said in the cemetery. Maybe if I did this wouldn't hurt so much. I_ _know_ _it wouldn't hurt so much if you were here, but I can't seem to bring myself to pick up the phone. I keep blaming on spotty reception, but I'm lying to myself and I know it._

 _I can't convince myself I don't need you. I keep trying to tell myself that I'm fine without you, but it's not working. I keep thinking back to what I was like before I met you, and even then you were affecting my life. I was so lost after my mother's death, and you were her favorite author. I've read all of your books so many times, it's almost embarrassing. When I realized I was going to have to bring you into the station that day, I was so excited. I knew I'd have to stay professional, so I did, but I don't think I expected you to be like you were. I mean I did, on a certain level, but at the same time I expected something other than what was on page six. God, this would be so much easier if I was a bestselling author, you know that?_

 _At least I know that I'll probably never get the chance to show you this, and even if I do I'll probably chicken out anyway. Knowing that, can I tell you how much of an_ _ass_ _you were back then. I mean you were constantly flirting, not that you don't do it anymore, but it's not the_ _only_ _thing you do now. It was like your only objective was to come off as the playboy they portrayed you as on page six, and any other one was to get me into your bed. You have no idea how much I wanted to give in, how much I wanted to grab you and have my wicked way with you. But I didn't. And I can tell you why._

 _When we were going over those letters and you did your Sherlock thing where you figured out my story without actually knowing me, I know you saw a part of me I didn't like people seeing, and I knew you felt bad about it. That was the first hint of the real you I saw, and I'm so glad I did. Part of the reason I didn't sleep with you was proving that you couldn't sleep with anyone you wanted, but another part was that I wanted to see if you'd show me the real you, not your publicity act. You have, and you didn't disappoint._

 _Slowly, through these last few years, you've shown me more and more of yourself, and I wish I could say it didn't matter. That way I wouldn't be so affected by what you said a month ago. I think I've known why it hurt so much for a while now. I've known why it hurt so much to see you with other women, even if I wasn't willing to admit it to myself. Even now, I can't seem to write the words down._

 _I wish so much that I had gone with you to the Hamptons that summer, instead of you leaving with Gina. I guess I never actually told you when I broke up with Demming. You probably think we broke up sometime during the summer, but you're wrong. I broke up with him right before your goodbye party. I had been planning on telling you that I had changed my mind and I wanted to come with you, had the offer still been open. Looking back, I know how I felt about you by then. Maybe I couldn't say it to myself, but the way it hurt when I watched you walk off with Gina, I knew I was in…_

 _When you came back after that and told me you were still with Gina, I can't help but wonder why you were so reluctant to tell me you were with her. It was like you were ashamed. I guess now I wonder if it isn't because of what you told me while I bled out in the grass. At the same time, I know that you being with someone else made me get together with Josh. I liked him, but in everything we did together all I could think about was what it would've been like if you were the one with me instead._

 _Josh being in Africa most of the time was one of the things that kept me with him. It was easy, he was gone most of the time, so we only ever talked over the phone. When he was in New York, he was still working long shifts, or I was working, so we still hardly saw each other. Don't get me wrong, I really liked him, just like I liked Demming, but he wasn't you. I cringe every time I think about the fact that I slept with him, because I know I was thinking of you the whole time, and it makes it so much worse. It's such a good thing he was gone so much, otherwise I don't think I could've pretended any longer. I know it was wrong for me to be with him, but I needed to prove to myself that I could be with someone other than you. I couldn't have been more wrong, I think._

 _You should know that I broke up with Josh as soon as I was out of the hospital and could actually talk to him for more than a minute. He was so protective while I was in there, and I really wish I hadn't strung him along like that. He was only a way of distracting myself from you. I was so worried that if I let you in, you'd break my heart, leave me a mess that no one could ever clean up. It's funny. I hated how much of a playboy you were in the beginning, but then I was relying on it as an excuse not to be with you. I kept telling myself it wouldn't last because you'd get bored as soon as the chase was over and we'd crash. I almost wish I'd been right. If I'd been right, you'd have left after the first book was finished. I was an idiot to keep thinking of it that way after the second book. It's almost_ _funny_ _how wrong I was. I was never even with you, and yet here I am, more broken than I was a month ago._

 _I got attached. That's the only way I'll let myself think of it. I guess I started thinking of you as permanent, and soon I couldn't think of what it'd be like without you. I so wish I didn't know now. A month without you, and even while the hole in my chest heals, my hearts breaks more every day. I'm being an idiot not picking up the phone, but now I don't think I can. I can't give you an explanation as for why I never called sooner. I don't want to go to you like this, even though I know you wouldn't care. I'm so broken, and I don't want you to see me like this, but the longer I stay away from you the worse it gets. I'm getting better at hiding how heartbroken I am, but like I said, my dad is getting suspicious._

 _I guess that at this point I've said enough that I don't think I even want you to read it, because it'll make you even angrier. I guess that means that since I'm at the point of no return and you'll never see this, I can say anything._

 _I love you. No. That's not even right. It doesn't have the weight I want it to. See, Castle, I've learned from you. Your writing habits have rubbed off on me. I'm_ _in_ _love with you. That's better. It captures my feelings the way I want it to. I've been in love with you since I broke up with Demming, at least that's as far back as I'm willing to admit. I don't think you understand just how far in I am, and the furthest we've ever gone was that undercover kiss._

 _I almost told you, once. When we were in that freezer and were about to freeze to death. I was about to pass out, and you were apologizing. I thought I was going to die, so I had nothing to lose. I was going to say that I want you to know how much I love you, but I guess I didn't get to finish. I wish I had. I wish Josh hadn't shown up. Before that, I had even told you that I wasn't happy with him. I wanted to tell you that you were the one I wanted to be with. The only reason I didn't was because I wanted to break up with Josh before I jumped you like that._

 _When we were in LA, I ran away to my room. I know you probably thought you scared me off, but I think I was more afraid of messing it up myself. I did go back. I opened up my door again. I wanted to say 'screw it' and kiss you like I'd been wanting to, but I opened my door just in time to see yours close. We were so close, Castle. I wanted to kiss you and make love to you while I told you how in love with you I was, but I didn't have the courage to knock on your door. I wish I had so much._

 _Now here I sit, barely able to move without wincing, and I don't think anything's ever hurt this much. I can't figure out if it's the pain from the bullet or the pain from you not being here that hurts worse. If you were here, this would be so much easier. My dad can take care of me, but he can't fix everything I've messed up with you. If you were here, I could tell you these things myself. We couldn't do anything, I'm not healed enough, but I could still tell you the thing that matters most. You told it to me every day with a cup of coffee, and I was too blind to see it._

 _In the cemetery, you told me you loved me._

 _I love you, too, Rick. I love you, too. Always._


	3. Chapter 3

**AN: I'm really sorry about how long this took, I truly am. I know it's long overdue, but in all fairness I was making sure I kept my other story going like it was supposed to, and those of you reading that one know even that has been a tad crazy. I actually wrote three different versions of this chapter, but I finally decided on this one. I'm not entirely convinced it's the best one, but I hope you enjoy this final chapter. Don't be afraid to send me a review or maybe even a suggestion for a new story!**

 **Disclaimer: I own no part of Castle.**

* * *

Castle's hands were shaking by the time he finished. The rest of the pages had writing on them, but he wasn't sure he could make it through fifty pages of Kate Beckett pouring her heart out onto a page. There was a good chance they were just thoughts throughout her day, and peeking at the next page, it didn't say "Dear Castle" at the beginning. It was probably just a regular diary after that, but at the same time, it was _Kate Beckett's diary_.

His mind was whirling. Knowing how she felt about him was making his heart pound, but knowing how long she had felt that way was on the verge of giving him a heart attack. He needed to call her, tell her he had her journal, but he wasn't sure he could do it without giving away that he had read it. Maybe it would be better if he told her he had read it. Maybe she would shoot him for invading her privacy.

She couldn't shoot him over the phone, but she'd still have to come over to the loft or he'd have to go to her. If he surprised her by showing up at her door, she wouldn't have time to get her gun ready.

He decided that going to her was his best plan, so he wrote a small note to Alexis and/or his mother if they were home before he got back, then hurried out the door before he could change his mind. His mind was going over the letter as he drove, and before he knew it, he was parking in front of her building.

He took the stairs in an attempt to burn away some of the nervous energy he had gained during his drive. When he reached her door, he took a moment to take a deep breath before knocking.

Castle rapped his knuckles on the door of the apartment, doing his best to keep his hand from shaking. He wiped his hands on his pants as he heard footsteps coming closer to the door. To say he was nervous would be an understatement. He had just read his partner's heart on a page, and he couldn't fight the feeling that she would ignore the meaning behind the words and scold him for ever reading something he knew was going to be personal.

The door opened slowly, creaking ever so slightly on it's hinges. From behind it came a fatigued-looking Beckett—no, a fatigued-looking _Kate_. Dressed in well-worn baby blue sweatpants and a ratty red t-shirt that was at least four sizes too big, Castle couldn't think of her as Beckett. Beckett was the hard-nosed detective that could win a staring contest with fear itself. _This_ was Kate—the caring, sweet woman underneath the pant-suits.

"Hey, Castle," she greeted with a tired voice. "What're you doing here?"

He couldn't answer her question, too distracted by an inquiry of his own. "Is that my shirt?"

Instantly her eyes widened and she looked down at her shirt, holding it out from her body between her thumb and index finger. "What? Um, I don't really know," she said, her voice uncertain of her own words.

"Now, now, Detective," he feigned scolding. "Don't lie to me. That's the shirt I gave you when you were staying in the loft after your apartment blew up."

"Fine," she huffed. "It's your shirt. Happy?"

He gave her a smirk. "I am, actually."

"If you want, I can give it back to—"

"No, no! Keep it; I've got plenty more at home," he assured.

"Was there an actual reason you came, or did you just come to annoy me?" she asked, putting one hand on her hip.

The reminder snapped him out of his smugness, and he was back to the same nervous state he was in before she opened the door. "Uh, yeah. Can I come in? I mean, I don't have to if you don't want me to, I just… Can I?"

She eyed him thoughtfully for a moment, her gaze suspicious of his sudden change in behavior. "Yeah," she said finally. "You want coffee?" She waved him inside, closing the door once he was standing awkwardly between her kitchen and living room. Rolling her eyes, she motioned to the couch, following behind him.

"No, thanks. I just want to…" he trailed off, not knowing if he should ask to talk to her about what she wrote right away.

"Want to…?" she prompted after a long silence.

"Sorry. I wanted to return this to you," he pulled the notebook from where it had been hidden in the inside of his jacket, handing it to her. "It fell out of your bag at the precinct and you were in the elevator by the time I noticed it under your desk."

Something flashed in her eyes, but she schooled her features too quickly for him to catch what it was. She reached for it with a forced calmness, as if she was afraid too move too fast, for what reason he wasn't sure. He suspected it was in an attempt to seem at ease in the situation, but the way her body immediately tensed the moment she laid eyes on the journal suggested otherwise.

"Uh, thanks, Castle," she said awkwardly. "I hadn't even realized it was missing; I guess I must've been too tired to notice."

"Speaking of you being tired, if you don't mind my asking," Castle started, "what was your appointment about today?" When she shifted in her seat, he gave her a way out. "You don't have to answer if you don't want to. It's none of my business."

She shook her head slightly, and his heart dropped for a moment before she spoke. "No, Castle, it's alright. I had physical therapy today; that's why I'm so exhausted right now."

"If you're too tired, Kate, I can leave." Castle pointed to the door as he spoke, keeping his eyes focused on hers.

After a moment's pause to think it over, she assured him he could stay. "It's really not a big deal. Plus, you're not a bad person to have around."

His answer came in the form of a grin. As much as he was worried about how she'd react to her journal being read, he couldn't hide his glee at the knowledge that she _wanted_ him there.

"Careful there," he said after a long moment of silence, "I might get the impression that you like me. Wouldn't want that going to my head, now would we?"

Again, something flashed in her eyes, but this time, it was something different, though he still wasn't sure what. "C'mon, Castle. I think we both know that I at least like you a _little_. Otherwise, I wouldn't keep you around."

There was a pause that seemed to hold them there, unable to move or speak. Deciding that it would be best not to tell her point blank he had read her diary, he went for a different approach.

"Can I ask what's in the notebook?"

He knew it was a long shot. The most he hoped for was a reason for it, a snarky comment about invading her privacy at least. The way she visibly tensed at the words only served to worry him more about whether the words in the notebook were true.

They had to be.

She nervously wiped her palm on her pants before speaking. "It, uh… It was sort of a way for me to talk about things without actually talking to anyone."

Castle forced himself to calm down and focus on what she was saying, not the fact that she was finally opening up to him.

"The first few pages are from this summer," she continued, albeit a bit hesitantly. "The ones after that I started writing when…" She trailed off, seemingly at war at herself over whether she should share this with him or not.

"When?" he prompted, knowing he had to snap her out of her trance before it engulfed her.

She picked at a loose thread on her shirt, but continued. "When my therapist, Doctor Burke, suggested that I should write what I can't say."

"What did you write about?" He was pushing his luck and he knew it. Knew by the way the words came out that it sounded less like a question and more like a challenge to see if she would tell the truth. This time, her eyes sparked with suspicion, but this time, it didn't fade. He knew she was catching on to him, could probably read it in his body language, but he stood his ground, and waited for the storm to come.

"Castle," she said in a low, warning tone. "Tell me you didn't."

He tried to feign innocence. "Didn't what?"

"Castle," she growled, standing from her seat.

"Sorry!" He held up his hands in surrender, following her lead and standing. "I swear I never meant to invade your privacy like that!"

"Then why did you read it? What reason could you possibly have?" She was fuming, and he knew that if he wanted to walk out of her apartment without a bullet in him, he needed to tread lightly.

He took a deep breath, and kept his voice calm. "I tried my best to leave it alone. My plan had been to wait long enough to be sure you were done with whatever appointment you had, then bring it over to you."

She opened her mouth to say something, but he held up a hand to stop her.

"I'm sure you know me well enough to know that it's hard for me to leave things alone, so I convinced myself that I would only read a line or two to figure out whether it was personal or work-related." She scoffed, but he continued without pause. "You know what's written on the first line, Kate. You know why I wouldn't be able to ignore _that_."

Her posture stayed in the same angry stance, but he could see that tears were welling up in her eyes, even as she looked away. He took a chance and walked towards her, only a couple feet away by the time he stopped.

"Kate?" he said softly.

"I'm alright, Castle," she told him, still not facing him. "I just…" She shook her head slightly, then turned her head towards him, but kept her eyes downcast. "I don't know what to do now. You know everything now, right?"

He chuckled. "I don't think I'll ever know everything. I told you that when we were in LA: you are the mystery I'm never going to solve."

"You said that's what you thought when we first met," she pointed out.

"Mere details," he responded, finally making her release a small laugh and look up at him. "I also said you amazed me."

"Do you still feel that way?" Her voice was small, as if she was afraid he might say "no".

"Of course," he assured. "Just look at you. You almost… You were shot and you're standing here in front of me." For some reason, it was easier to say she had been shot rather than that she had almost died.

Kate rubbed at the scar at the mention of that fateful day in the cemetery. "So where do we go from here?" This time, when she met his eyes, she looked hopeful.

"Wherever you want, Kate."

She took a deep breath, closing the small gap between them to fiddle with his collar. "You remember what I said at the swings?"

Rick nodded. "Of course."

"I don't want to wait for those walls to come down. You already made your way inside, anyway." She gave him a small smile, then brought a hand up to his shoulder.

Deciding that at this point he didn't have to be worried about her pulling out her gun, he placed his hands on her hips. "So, we're finally doing this?"

She nodded. "I think it's about time."

There was a long silence as they gazed into each others' eyes, before Rick finally broke it with a whisper.

"I love you so much."

Her grip on his shoulder tightened for the briefest of moments, then she rose up on her toes, bringing her lips mere inches from his.

"I love you, too," she said softly before pressing her mouth to his, ready to finally take that leap.


End file.
